After several months of preparations and setting up our system, we have produced our first ultracold atomic cloud of erbium atoms in our new T-REQS lab. After initial slowing down in a Zeeman slower with a broad transition, we trap and cool 166Er atoms in a 5 beam magneto-optical trap operating on the narrow linewidth transition at 583nm. We trap up to 120 million atoms and cool them to ~15 microkelvin in a compressed MOT phase. This is a first step on our way to trapping ultracold erbium atoms in optical tweezers.
Applications have now opened for the Introductory Course on Ultracold Quantum Gases 2022 winter school. This will take place in Innsbruck between the 9th and 11th February 2022. Please visit the website for more information and to apply.
Figure: Experimental realisation of a two-dimensional seven droplet hexagon state. (a) In-situ image of density profile. (b) Image after 36 ms time-of-flight expansion. (c,d) Corresponding theory result for the same trap. In (d), the time-of-flight expansion is estimated by a Fourier transform of the wavefunction.
Dipolar condensates were recently coaxed into supersolid phases supporting both superfluid and crystal excitations. The first dipolar supersolids consisted of one dimensional droplet arrays, and a recent experiment here achieved two dimensional supersolidity, observing the transition from a linear chain to a zig-zag configuration of droplets.
In this work, in collaboration with Prof. Luis Santos from the Leibniz University Hannover, we show that while one-dimensional supersolids may be prepared from condensates via a roton instability, such a procedure in two dimensions tends to destabilise the supersolid. By evaporatively cooling directly into the supersolid phase–hence bypassing the roton instability–we experimentally produce a 2D supersolid in a near-circular trap, an observation verified through state-of-the-art finite temperature simulations. We show that 2D roton modes have little in common with the supersolid configuration, instead, unstable rotons produce a small number of central droplets, which triggers a nonlinear process of crystal growth. We calculate excitations for a 2D supersolid ground state, and make comparisons with 1D arrays using the static structure factor. These results provide insight into the process of supersolid formation in 2D, and define a realistic path to the formation of large two-dimensional supersolid arrays.
In recognition of her outstanding achievements, Francesca Ferlaino was elected a Corresponding Member of the Mathematical and Natural Sciences Class of the Austrian Academy of Sciences.
The Austrian Academy of Sciences (ÖAW) strengthens its ranks with 31 newly elected members. In this year’s elections, 19 female and 12 male researchers from a wide variety of disciplines in the humanities, social and cultural sciences as well as mathematics, natural and technical sciences were awarded membership in the ÖAW for their outstanding scientific achievements. Francesca Ferlaino’s research explores quantum phenomena in atomic gases at ultralow temperatures with contributions spanning topics including quantum matter of atoms and molecules and few-body and scattering physics. Her work has earned her multiple awards, including the prestigious Feltrinelli Prize, the Grand Prix de Physique “Cécile-DeWitt Morette/École de Physique des Houches” from the French Academy of Sciences, the Junior BEC Award, and the Erwin Schrödinger Prize, the highest award of the Austrian Academy of Sciences. In addition, she is recipient of an Alexander-von-Humboldt Professorship, a START-Prize and two ERC Grants (Starting and Consolidator).
Russell has been awarded one of only six ESQ Discovery Project grants this year. The Discovery Programme supports new ideas and innovative research that go beyond traditional thinking.
